Question : Outlook Anywhere authentication, basic or NTLM - why either or and not both?

So we've always used RPC over HTTPS for our Outlook clients.  Has always worked great - we used a front end Exchange 2003 box and we had authentication set for both NTLM and basic.  Reason for this is we had most of our Outlook clients on domain machines, so we were good with NTLM.  We also had basic so a few people could use home machines and enter in their credentials.

Now with Exchange 2007 SP1 on a CAS, we see we only have an option for basic or NTLM, not both.  Did some Googling and found the Exchange team reinforcing this.  What we can't find is a reason why.  We'd like to have both turned on, and we're tempted to change it manually, but would like more info first.

Answer : Outlook Anywhere authentication, basic or NTLM - why either or and not both?

So I spoke with Microsoft.  The "engineer" I spoke with was less than helpful.  In testing, we found that we could actually use NTLM authentication on the machines that were NOT on the domain.  I asked her if this was accurate, and she agreed after thinking about it.  I asked if this had changed from Ex2003, and she agreed, after checking with someone.  She wasn't really sure and just agreed with what I had to say.

So in the end, we just had to adjust any basic authentication clients to perform NTLM authentication and we seem to be fine.